This 2003 Chevrolet Trailblazer had a loud ticking noise coming from the rear of the vehicle on the passenger side. In the last post I showed how to remove the trim panels and locate the faulty actuator assembly. Please click here to see that part of this repair.
Once the trim panels were removed it was just a matter of feeling the clicking in the actuator.
The thumb latch has to be depressed to release the harness connector.
There are a total of three phillips headed screws that hold the actuator in place.
It took a little bit of wiggling around but the actuator pulls straight up off of the mode door shaft. The old actuator had several part numbers on it; 47210105, 0297707 and AH24102002. If you want to purchase the most up to date replacement actuators please click here.
I manually turned the shaft to make sure the door moved freely.
Notice the shaft has a half round section with a perpendicular tab to one side. There is a matching recess in the actuator assembly.
When voltage testing, I use an angled pick to probe the harness wires individually. I then clip my meters test lead to the pick.
There are various designs and many are useful for this kind of testing.
Now that the actuator has been replaced the system should be recalibrated. The standard Trailblazer or Envoy would need the driver’s side rear seat cushion lifted to access the fuse box. The vehicle is an EXT version and the whole seat flips up to access the interior fuse box.
There are two push pin retainers that have to be removed as shown below.
I had to locate the fuse labeled “HVAC B” on the fuse box legend.
I had to orient the legend to align the picture with the actual fuse box components.
Once I had located the proper fuse I removed it to start the recalibration process.
The key must be off before the fuse is removed.
Leave the fuse out for one minute.
Install the previously removed fuse.
Turn the ignition on for one minute.
Put your hands in your pockets and Do Not Touch Anything while the ignition is on.
Turn the ignition off for at least ten seconds but no more than thirty seconds.
Turn the ignition on and start the engine. Test the actuator for proper function.